The announcement that Egypt´s armed forces chief Field Marshal
Mohamad Hussein Tantawi and his number two, Sami Annan, were being
forced to retire caught the nation by surprise.

In total, seven members of the military´s top brass were removed from
their posts.

At a late afternoon news conference shown on state television, the
presidential spokesman also stated that a controversial
constitutional declaration issued in June had been cancelled.

It was an attempt by the Supreme Council of the Armed Forces (Scaf),
when it was still ruling the country, to limit the president´s powers.

"This move will enter history as a significant shift in the civil-
military balance of power towards the civilian side," says Omar
Ashour, a Middle East expert at the Brookings Doha Centre and Exeter
University.

"This is the first time in Egypt´s political history that an elected
civilian politician overrules the decisions of the heads of the
military establishment."

What is not clear is whether President Mohammed Mursi co-ordinated
his actions with the armed forces.

Some analysts have suggested that he must have got the agreement of
Field Marshal Tantawi and Gen Annan as it was said that they would
continue to act as his advisers.

´Constitutionally correct´

It also seems clear that other members of the Scaf gave their
approval. Gen Abdel-Fattah al-Sisi, who has already been sworn in as
the new defence minister, replacing Field Marshal Tantawi, sat on the
council as the former head of military intelligence.

Questions have been asked about Mr Mursi´s constitutional powers to
act. But a retired brigadier general, Ayman Salama, who is also an
expert on international law says he went about things correctly.

"He went about this in a constitutional way by cancelling the
constitutional declaration in order to make these decisions," he told
the BBC.

The new measures take effect just as Egypt´s armed forces are
involved in their biggest deployment in the Sinai region for decades.

They were unprepared for an attack there last week that saw 16
Egyptian border guards killed by militants.

Mr Mursi appears to be seizing on that failure - which shocked the
public - to take his decisive political action.

Speaking at an event for the Islamic holy month of Ramadan he
insisted that he was not targeting "certain individuals" but was
looking out for "the country´s best interests", leaving the military
to concentrate on its job of protecting the country.

Already large crowds of his supporters have returned to Tahrir Square
in Cairo to celebrate the latest developments.